Cargo vessel



Match 6, 1928. 1,661,855

, c. RITSON CARGO VESSEL Filed July 2'7. 1926 2 Sheets-Sheet 1 March 6, 1928. 1,661,855

' c. RITSON AReo VESSEL Filed July 27. 1926 2 Sheets-Sheet 2 Inventor.

Patented Mar. 6, 1928.

1 UNITED STATES PATENT oF icE. 1

CUTHIBERT RITSON, F BLYTE, EEGLANID.

CARGO VESSEL.

Application filed July 27, 1926, Serial No. 125,230, and in Great Britain August 5, 1925.

This invention relates to cargo vessels, and has for its object to provide an improved construction of cargo vessel whereby the cargo-carrying capacity of the vessel is inn creased as compared with a vessel of the same moulded dimensions constructed according to existing shipbuilding practice, the increased cost of construction being more than compensated for by the augmented earn- 1 ing power, increased utility and greater seaworthiness and strength of my improved vessel.

According to my invention I provide a fore-and-aft deck rising; from the upper deck having inwardly inclined sides above the.

upper deck which confine the upper portions of the holds in a iore-and-att't direction, said inclined sides supportingand elevating the coamings of the hatchways substantially above the deck to increase the cargo spaces. The plating of the inclined sides is sup ported by inclined beams which are separate from but strongly connected to the usual side framing of the "essel' and at their upper ends to the outsides of the hatch coamings. Platforms are provided as usual between and at the ends of each set of hatchways. Fore-and-aftgangways are provided along the sides of the hatchways supported by so nal contour thereof and are separate from but connected to the inclined beams and to the hatch coamings, the inclined plating of the sides of the deck erection being continued over the gangways and platforms. A thwartship tank is disposed between each pair of elevated hat-chways, said tank having upwardly diverging sides which confine the upper portions of the holds in a thwartship direction andextend up to the elevated hatch coamings, the ends of said tank being closed above the upper deck by the inclined sides of the deck erection and below said deck by the sides of the vessel.

The thwartship tanks may extend both above and below the upper deck of the vessel. A

thwartship tank may. also be provided at.

the end of each set of hatchways, one side of said tank being inclined towards the hatchways and extending up to the elevated hatch coamings. The angle of inclination of the sloping sides of the deck erection and of the thwartship tanks is approximately that of the angle-of-restof the cargo for which the vessel is intended (which may be structural members which follow the intergrain, coal, coke or other bulk cargo), and the hatchways are raised by said sloping sides above their customary level thus providing additional cargo space to an amount which exceeds the loss ofspace due to the to thwartship tanks, where these are fitted. The additional buoyancy obtained by the deck erection enables the itreeboard of the vessel to be reduced and the deadweight to be correspondingly increased.

. F ore-and-aft side tanks may be fitted if desired, said side tanks being disposed below the upper deck and externally otthe inclined sides of the deck erection, and, where said fore-andaft tanks extend across the thwartship tanks, the ends oi. thelatter below the upper deck are closed by said side tanks. The side tanks may however stop at the thwartship tanks.

The portions of the thwartship tanks above the upper deck 'i'nay in some cases form deck erection spaces and be used for cargo spaces.

The cargo can be loaded in bulkinto the holds of my improved vessel. and it will fill 39 the cargo spaces'without it being necessary to trim the cargo except to level it oh flush with the top of the hatch coamings or so much below same as may be desirable.

I will further describe my invention with reference to the accompanying drawings wherein Figure 1 is a central longitudinal section and Figure 2 a deck plan of a singledeck cargo vessel according to my inven- .tion, Figure 3 is a trasnverse section thereof, i

the left-hand half in the way of a hatchwa-y and the right-hand half in the way of a thwartship tank, and Figures 4- and 5 are respectively a part longitudinal section and'a part transverse sect-ion, to. a largerscale, illustrating the internal construction of a tl'iwartship tank therein. Figure 6 is a part similar view to Fig. 3 illustrating a modified construction in which the vessel is fitted with I fore-and-aft side tanks, and Figure 7 is a 10 transverse section in the way of a hatchway of a tween deck vessel, the left-hand'half showing the vesselwithout side tanks and the right-hand half showing the vessel fitted 'withside tanks. Figure 8 is a part similar view to a larger scale of the left-hand half of Fig. 7 illustrating a detail,andFigure' 9" is a section on the line X--Y therein.

Referring to the said drawings, in the single-deck cargo vessel illustrated in Figs.

1 t0 5, a are the th\\'artship tanks which are provided between the hatchways band at the fore and after ends thereof, said tanks extending both above and below the upper deck 0. The plating d separating the tanks a from the upper portions of the holds 0 is inclined approximately according to the angle-of-rest of the cargo for which the vessel is intended. The internal construction of the thwartship tanks is best shown in Figs. 4' and 5. The plating (Z is attached at the top to the bottoms of the hatch coamings b and is strengthened by inclined frames (5. At the bottoms of the tanks, the frames d and plating (Z are attached by brackets (Z to hold beams 7 which are connectcd by brackets f to web frames 9 at the sides of the vessel. The tanks 11 arestitfened by a lattice work of bars and brackets (1 At the top. the thwartshi ii tanks are closed in by platforms it between the hatchways 7) and at the fore and after ends thereof, said platforms providing the necessary space and support for the usual deck machinery and fittings.

The fore-and-aft deck erection is formed by plating carried by inclined frames 9', the bottoms of which are bent horizontally and attached by brackets to the side frames 70 of the vessel. The tops of the frames 1', in the way of the hatchways, are connected to the bottoms of the hatch coamings b and, in the way of the thwartship tanks, they are connected by brackets j to the platforms 71 The plating j and framin; j are inclined approximately according to the angle-of-rest of the cargo for which the vessel is intended. The plating j is connected to the upper deck plating o by fore-and-aft angle bars 0 (Fig. 4).

At the sides. the thwartship tanks at are closed by the inclined plating 7' above the upper deck 0. and by the side plating a of the vessel below said deck.

The frames 7' also carry top bars m supporting fore-and-aft :Iane'ways m which run alongthe sides of the hatchways 7) and platforms 71. to meet the forecastle bulkhead n the. fore bridge deck bulkhead 11. the after bridge deck bulkhead w and the poop bulkhead n. the plating oi the gangways being carried down as shown to meet the plating 7' and forming an integral portion of the deck erection which is stiffened in the foreand aft direction by said gangways. Brackets may be substituted for or provided in addition to the bars m If desired, and as illustrated in Fig. 6, the vessel may also be provided with foreand-aft side tank p below the upper deck 0 and outside of the inclined sides 7' of the deck erection. said side tanks being formed by downwardly extending the. inclined side plating and frames 7' The side tanks 72 may stop at the thwartship tanks (1, in

which case the construction in the way of a thwartship tank is as shown in the right hand half of Fig. 3, or the side tanks may be continued past the thwartship tanks, in which case the construction is as shown in the right-hand half of Fig. ti, the thwartship tanks being closed by the extended inclined plating j.

here the vessel is double-decked and is provided with tween decks q or a long bridge deck as illustrated in Fig. 7, the construction, whether without side tanks (lefthand half) or with side tanks (right-hand half), is substantially the same as that above described in connection with a single-decked ship. The inclined side plating entirely separates the main holds a from the tween decks. means of access to the latter being obtained by fitting extra independent hatchays g in the deck 7*. Sliding doors 8 (Figs. 8 and 9) are provided in the plating j adapted to be raised and lowered, when required, by suitably mounted gearing a from the deck 1' to open and close the dween decks, whereby cargo in the twern decks an be discharged into the main holds.

Access to portions of the thwartship tanks 0 above the upper deck 0 may be provided for by manholes or hatchways in the platforms h, in which case the portions of said tanks below the deck 0 will be sealed from the upper portions, but in the case of? heavy -argoes such as iron ore, the whole of the thwartship tanks may be sealed to obtain additional buoyancy.

By way of illustration of the advantages of my improved construction, I will take as an example a cargo vessel of the type illustrated in Figs. 1 and 2 having moulded dimensions of 245 feet by 37 feet 6 inches by 19 feet 6 inches, and a deadweight of approxin'iately 2300 tons. \Vithout in any way altering the moulded dimensions of this vessel. I adapt it to embody my invention bv positioning the hatehways in the fore-andaft and in the thwartship directions so as to give the desired angle of the sloping sides of the deck erection and thwartship tanks. and 1 make these hatchways about 5 feet 6 inches above the upper deck as compared with the customary practice of disposing the hatchvays level with the deck. I then carry the sloping sides of the thwartship tanks below the upper deck to a depth of about 3 feet 6 inches.

If T fit one thwartship tank between Nos. 1 and 2 hatchways and one between Nos. 3 and 4 hatchways, the capacitv of the hold is reduced by about 65 tons. Moreover it will be found necessary in this particular vessel. in order to obtain the required angle of slant of the ends of the holds, to move the forward bulkhead 71. one frame space further aft than is usually done and the boiler room bulkhead a one frame space forward.

iii

This causes a further reduction in the capacity of the holds of about 20 tons. I

To compensate for this loss and to gain the increased earning powerhereinbcfore mentioned, I make the superstructure above the deck 0 of a capacity, after allowing for the above deductions, of about 160 tons, which amount includes the weight of the extra material used. This additional deadweight is permitted owing to the increased buoyancy and the consequently reduced free board obtained, which reduction in this case is about 9 inches.

A cargo vessel with its upper structure arranged and constructed as herein described is completely self-trimming; bulk cargo, such, for example, as coals or grain, filling close up to the Walls of the inclinedupper portions of the holds as it is loaded and requiring only to be levelled off at the hatch coamings, the vessel thus requiring less time for loading and discharging with a conse quent saving in expense over existing types of vessels of similar moulded dimensions.

There are few obstructions in the holds and hence less likelihood of damage when grabs are used. Stowage of the cargo is facilitated, and possibility of the cargo shifting in bad weather is minimized.

The sea-worthiness and strength of the vessel are increased by reason of the addi-' tional buoyancy and other advantages-due to the inclined sides and thwartship tanks which form a superstructure higher than the usual hatch coamings. Less water will lodge on the deck in bad weather and it Will be more quickly cleared oil, thus reducing strains on the deck and possibility of damage. The raised gangways m provide safe and easy passage to-and-fro on the ship.

In the case of a tween deck vessel or one having a long bridge deck, the twecn deck portions 9 can be made without hatchways to the tween deck at the sides whichportions then form watertight compartments thus increasing the reserve buoyancy and decreasing net tonnage when heavy bulk cargoes are carried and adding to the seaworthiness and safety factor of the vessel. \Vhen the ship is in ballast, the tanks may be filled with water ballast to the required extent thus improving the behaviour and speed of the vessel under these conditions.

Greater strength is obtained in both foreand-aft and thwartship directions by my system of construction, a strut being formed at the junction of the thwartship tanks at and the fore-and-aft inclined plating j of the deck erection as shown in dotted lines at m in Fig. 2, which transmits in both directions simultaneously the stresses of heavy seas coming inboard, the structure forming a complete girder. The gangways m, in addition to providing additional buoyancy and safety at sea, add considerably to the strength, and the upper structure will'stand more strain than in the existing types of cargo vessels. l

\Vhat I claim as my invention, and desire to secure by Letters Patent is 1;:[1121 cargo vessel, a fore-and-aft deck erection rising from the upper deck and having inwardly inclined sides above said deck which confine the portions of the cargo space above the deck in a fore-and-aft'dil'ection, hatch coamings supported by said inclined sides whereby the hatchwaysare elevated substantially above'the deck to in crease the cargo spaces, inclined beams supporting the plating of said inclinedsides separate from but strongly connected to the usualside framing of the vessel and at their upper ends to the outsides-of the hatch coamings, and platforms between and at the ends of each set of elevated hatchways.

2. In a cargo vessel, a fore-and-aft deck erection rising from the upper deck and having inwardly inclined sides above said deck which confine the portions of the cargo space above the deck in a fore-and-aft direction, hatch coamings supported by said inclined sides whereby the hatchways are elevated substantially above the deck to increase the cargo spaces, inclined beams supporting the plating of said. inclined sides separatefrom but strongly connected to the usual side framing of the vessel and at their upper ends to the outsides of the hatch coamings, platforms between and at the ends of each set of elevated hatchways, fore-and-aft gangways along the sides of said hatchways, and structural gangways and following the internal contour thereof, said structural members being separate from but connected to the inclined beams and to the hatch coamings, the inclined plating of the sides of the deck erection being continued over the gangwaysand platforms. p

3. In a cargo vessel, a fore-and-aft deck erection having inwardly inclined sides above the upperdeck which confine the upper portions of the holds in a forc-and-aft direction, hatch coamings supported by said inclined sides whereby-the hatchways are elevated substantially above the deck to increase the cargo spaces, platforms bet-ween and at the ends of each set of elevated hatchays, means for stiffening said deck erection in the fore-and-aft direction, a thwart ship tank between each pair of elevated hatchways, said tank having upwardly diverging sides which confine the upper po tions of theholds in a thwartship direction and extend up to the elevated hatch coamings, the ends of said'tank being closed above the upper deck by the inclined sides of the deck erection and below said deck by members supporting said til erection having inwardly inclined sides above the upper deck which confine the upper portions of the holds in a fore-and-aft direction, hatch coamings supported by said inclined sides whereby the hatehways are elevated substantially above the deck to in crease the cargo spaces, platforms between and at the ends of each set of elevated hatchways, and means for stilteninp said deck erection in the fore-and aft direction, a thwartship tank between each pair of elevated hatchways, said tank extending both above and below the upper deck of the vessci, and having upwardly diverging sides which confine the upper portions of the holds in a thwartship direction and extend up to the elevated hatch coamings, the ends of said tank being closed above the up per deck by the inclined sides of the deck erection and below said deck by the sides of the vessel.

5. In a cargovessel, a fore-and-att deck erection having inwardly inclined sides above the upper deck which confine the upper portions of the holds in a fore-and-aft direction, hatch coainings supported by, said inclined sides whereby the hatchways are elevated substantially above the deck to increase the cargo spaces, platforms between and at the ends of each set of elevated hatchways, and means for stiffening said deck erection in the fore-and-aft direction, a thwartship tank between each pair of elevated hatchways, and a thwartship tank at the end of each set of hatchways, at least one side of each of said tanks extending up to, and being inclined towards the hatch coamings, said inclined sides confining the upper portions of the holds in a thwartship direction, the ends of said tanks above the upper deckbeing closed by the inclined sides of the deck erection and below said deck by the sides of the vessel.

(3. In a cargo vessel, a fore-and aft deck erection having inwardly inclined sides above the upper deck which conline the upper portions of the holds in a fore-and-aft direction, hatch coan'iings supported by said inclined sides whereby the hatchways are elevated substantially above the deck to increase the cargo spaces, platforms between and at the ends of each set of elevated hatchways, and means for stiffening said deck erection in the fore-and-aft direction, a thwartship tank between each, .pair of elevated hatchways, and a th\vartship tank at the end of each sctoi hatclnvays, at least one side of each of said tanks extending up to and being inclined towards the hatch coainings, said inclined sides confining the upper portions of the holds in a tlnvartship direction, the ends of said tanks above the upper deck being closed by the inclined sides of the deck erectionainl below said deck by the sides of the vessel, and tore-and al't tanks disposed below the upper deck and externally of the inclined sides of the deck erection.

In testimony whereof, I aliix my signatnre.

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